The aim of the Pediatric Clinical Research Center is to provide facilities for intensive and sustained investigation of the basic mechanisms of growth, maturation, and the pathogenesis of disease in children. The long term objective, of course, is the prevention and cure of disease--not only disease conditions clinically frequent in this age group, but also degenerative disorders of later life which have their subclinical beginnings in childhood. The assumption being made is simply that of all health-related research at a basic level, an increased understanding of physiological and pathological mechanisms will lead to a rational basis for prophylaxis and therapy. The investigations encompassed by this application have been or will be approved by the committee of associates of the investigator(s) in accordance with this institution's assurance on clinical research dated 9/20/66.